A Method for Packaging a Micro or Nano Electro-mechanical System Device
A conventional method for packaging a micro electro mechanical system (MEMS) device or a nano electro mechanical system (NEMS) device is performed as follows. First, after an MEMS device or an NEMS device is manufactured on a substrate, a sacrificial layer is formed to cover the device. Then, a thin film layer for removing the sacrificial layer is formed on the sacrificial layer. Subsequently, an etching hole is formed in the thin film layer, and then the sacrificial layer is removed through the etching hole. The sacrificial layer can be removed by using a wet etching process or a dry etching process. Next, a shielding layer is formed to surround the thin film layer so that the device is packaged.
Such a packaging method needs a process of forming the etching hole in the thin film layer in order to remove the sacrificial layer. Here, the etching hole is formed in a position adjacent to the edge of the device. In this case, there are problems in that it takes a large amount of time to remove the sacrificial layer and in that the device may be damaged physically or chemically.
A Method for Forming a Nano Wire
Among conventional methods for forming a nano wire, there is a method using a template including a vertical nano-sized pore. Here, an etching method and an anodizing method and the like can be used for forming the template.
The etching method is to porously etch a silicon substrate by using an electro-chemical method. The anodizing method is to form a vertical nano-sized pore in metallic material such as Al or Ti and the like.
Said methods are simple and inexpensive compared to a conventional reactive ion etching (RIE) method and the like. However, they require a porous etching process and an anodizing process.
A Method for Forming a Hydrophobic Surface
A conventional method for forming a hydrophobic surface or a super-hydrophobic surface includes a method performed as follows. A micro-sized pattern or a nano-sized pattern is formed, and then another pattern is made of polymer such as Polydimethylsiloxane (PDMS) and the like by using a replica method.
A top down method or a bottom up method and the like is used for forming a micro-sized pattern or a nano-sized pattern.
The top down method includes a templating process, photolithography and a plasma process and the like. The bottom up method includes a chemical vapor deposition, a colloidal assembly layer-by-layer deposition and a sol-gel method and the like. Such methods require not only an additional patterning process of the template but payment for using expensive processes such as the photolithography, an electron beam photolithography or a nano imprint and the like.